In recent years, development of display has shown a trend of high integration and low cost. One extremely important technology is applying the GOA technology into mass production. The GOA technology is adopted to integrate a gate switching circuit on an array substrate of a display panel so as to omit a gate drive integrated circuit part, such that production cost can be reduced in terms of both material cost and manufacturing process. The gate switching circuit integrated on the array substrate by the GOA technology is referred to as a GOA circuit or a shift register circuit.
The GOA circuit comprises a plurality of GOA units, each of which comprises several thin film transistors (TFTs). Each of the GOA units corresponds to a gate line, and particularly each of the GOA units has an output terminal connected to its corresponding gate line. Since the GOA circuit has to be implemented by a large scale integrated circuit IC, how to control the scale of the IC while ensuring the performance of the GOA circuit has became a development trend of the GOA circuit.